Or
did a breakdown in military-civilian communication lead to a fatal delay
in fighter-jet interception?

Or
both?

On
Tuesday, terrorists commandeered four commercial airliners, crashing
two of them into the World Trade Center and one into the Pentagon.

But
the nation's air defense system - which in the northeastern United States
is spearheaded by the 102nd Fighter Wing at Otis Air National Guard
Base - is oriented toward meeting external threats.

The
North American Aerospace Defense Command, or NORAD, which coordinates
continental air defense, "is not normally focused inside the continental
United States," according to a spokesman.

Tuesday,
however, the threat came from within NORAD's perimeter -not outside
of it.

FAA-military
communication Under the current system, the Federal Aviation Administration,
which monitors domestic flights, notifies NORAD about serious problems.

FAA
controllers became aware Tuesday morning that hijackings were underway.
Five days later, the question lingers whether the FAA notified NORAD
as quickly as the agency could have, or should have.

Thursday,
the Christian Science Monitor reported that air traffic controllers
at a Federal Aviation Administration center in Nashua, N.H., were aware
soon after the first of the airliners took off that something was amiss.

That
airliner, an American Air Lines Boeing 767, was Flight 11 from Boston
to Los Angeles. It departed from Boston's Logan International Airport
at 7:59 a.m.

About
15 to 20 minutes west of Logan, the Monitor reported, the controller
gave Flight 11 permission to climb from 29,000 feet to 31,000 feet.
But the plane didn't climb.

After
issuing a further request to climb - which again met with no response
- the controller sought to communicate with Flight 11 on an emergency
channel.

Still
no response. Then the plane stopped sending a radar pulse.

"Then
the plane turned [south toward New York], and then they heard the transmission
with the terrorist in the background," said a controller at Nashua
interviewed by the Monitor.

"The
voice upset him [the controller] because he knew right then that he
was working a hijack," the controller told the Monitor.

If
a problem is detected, what protocol is a controller supposed to follow?

"The
air traffic controller would notify the supervisor on the floor, who
would then immediately notify the FAA's regional operation center who
would notify NORAD, as well as others," an FAA spokeswoman, Alison
Duquette, said Friday.

Surveillance
of hijacked craft The 102nd always has two F-15 fighter jets on 24-hour
alert, according to the wing. The wing also is specifically charged
with protecting the northeastern United States, including New York City
and Washington.

Would
the wing's jets be prepared to close in on a hijacked airliner?

"We
also provide surveillance of hijacked aircraft and assist aircraft in
distress," the wing has stated.

The
errant airliner's flight lasted 46 minutes Tuesday, between taking off
in Boston and crashing into the North Tower of the World Trade Center.

Based
on the Monitor account, the FAA would have been aware of a problem for
perhaps the last 20 minutes or so of the flight.

An
FAA spokesman yesterday declined to comment whether the Monitor's account
was accurate.

"We're
not releasing any details," he said.

Yesterday,
however, a NORAD spokesman confirmed that the FAA notified NORAD of
a hijacked aircraft.

The
spokesman, Maj. Mike Snyder, said NORAD was notified about 10 minutes
before Flight 11 hit the World Trade Center.

That
notification would have come around 8:35 a.m. The airliner hit the North
Tower around 8:45 a.m.

An
F-15 Eagle can fly at about three times the speed of a 767. An F-15
departing from Otis can reach New York City in 10 to 12 minutes, according
to an Otis spokewoman.

Neither
NORAD nor the 102nd will comment on whether the wing scrambled to intercept
any of the airliners.

"We're
not discussing any operational details," Snyder said yesterday.

Was
interception possible? Published reports Friday and yesterday said that
Otis jets did scramble to intercept the hijacked airliners, although
the reports gave differing times for that action.

LHThe
first crash, of Flight 11, arguably was too unexpected to stop.

But
what about United Airlines Flight 175, which left Boston 15 minutes
after Flight 11?

Flight
175 departed off its course over Connecticut, 16 minutes into its flight,
according to USA Today.

The
United flight was over central New Jersey when it turned and headed
northeast, back toward Manhattan, USA Today reported. Radar contact
was lost between Philadelphia and Newark.

Forty
minutes after its Boston departure - and 16 minutes after Flight 11
hit the North Tower of the World Trade Center - Flight 175 hit the center's
South Tower.

Forty-nine
minutes later, at 9:50 a.m., the South Tower collapsed. The North Tower
collapsed at 10:29 a.m. Nearly 5,000 people have been reported missing
since the collapse of the towers.

Could
have - should have - F-15s shadowed the errant Flight 175, especially
after Flight 11 already had hit the World Trade Center?

If
not, why not?

F-15s
from Otis also are responsible for protecting national command centers
in Washington.

At
8:10 a.m., according to the Washington Post, American Airlines Flight
77 departed from Dulles Airport in Washington, D.C.

Flight
77 also deviated from its course. According to the Dallas Morning News,
military officials scrambled three F-16s from Langley Air Force Base
in Virginia to intercept the airliner.

But
the intercept failed.

About
90 minutes after its departure from Washington - and almost 40 minutes
after the second World Trade Center crash - Flight 77 hit the Pentagon.

The
fourth airliner - United Flight 93 - departed from Newark, N.J., at
8:01 a.m. for San Francisco.

After
Flight 77 hit the Pentagon, controllers watched as Flight 93 took a
turn in western Pennsylvania and headed for Washington.

That
airliner, however, apparently fell from the sky and crashed in southern
Pennsylvania at 10:10 a.m.

The
crash may have been the outcome of a struggle between passengers and
the hijackers, the Washington Post has reported.